Function _mm256_mask3_fmsubadd_pd
#[target_feature(enable = "avx512f", enable = "avx512vl")]
pub const fn _mm256_mask3_fmsubadd_pd(a: __m256d, b: __m256d, c: __m256d, k: __mmask8) -> __m256dMultiply packed double-precision (64-bit) floating-point elements in a and b, alternatively subtract and add packed elements in c from/to the intermediate result, and store the results in dst using writemask k (elements are copied from c when the corresponding mask bit is not set).